The purpose of this manuscript is to describe the consistency in the frequency of five health outcomes across the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD‐9‐CM) and Tenth Revision, Clinical Modification (ICD‐10‐CM) eras in the US. The authors examined the incidence of three acute conditions (acute myocardial infarction, angioedema, ischemic stroke) and the prevalence of two chronic conditions (diabetes, hypertension) during the final five years of the ICD‐9‐CM era (January 2010‐September 2015) and the first 15 months of the ICD‐10‐CM era (October 2015‐December 2016) in 13 electronic health care databases in the Sentinel Distributed Database.